Terraqua offer a range of Eel pass systems
These permit Eels to migrate up-stream from the sea to rivers.
Prefabricated gutter
Prefabricated screens are used to fit eel passes to mobile dams. They are made of polyester and covered with an eel substrate. Brackets are used to fix them to the vertical wall of the dam. Their installation must be adapted to suite the configuration of the site, to the drop and its fluctuations. Upstream, the screen opens into the dam lake or a canal emptying into it which goes around the solid structure of the dam. The length of the screens is adjusted to fit the drop by the use of extensions. A preliminary study determines the configuration of the upstream outlet, the wedge and the length.
Download data sheet Pre-fabricated crawling gutter
Eel pass for flood gate
This pass is fixed to the top of the globe valve, and has to be fitted to it. The ramp is mobile; its downstream portion follows the fluctuations of level by means of a float. It can cope with the total lowering of the clapper. An upstream hood protects the equipment. This pass is suitable for small drops (less than 0.80 m) and to low flow rates (marshy areas). The pass is fixed to the clapper by means of zip fasteners that are attached to the valve; it can be dismounted.
Dimensions: 1.60 X 0.50 m. Weight: 18 Kg
Materials: polyester support in galvanised steel
Download data sheet Eel pass for floodgate
Eel pass for rising gates
This low-tech pass is attached to the top of the rising gate, which is set to 0.05 to 0.10 m of hydraulic head over the point where the outflow starts. This pass is suitable for small drops (less than 0.80 m) and low flows (marshy zones)
Dimensions: 1.60 X 0.30 m
Weight: 15 Kg
Materials: Pre-pierced polyester for fixing. Fixed by bolts, mounting bolts…..
Download data sheet Eel pass for rising gate
Modular eel passes
This type of pass includes prefabricated eel gutters and various different types of resting pools that can be adapted to the situation.
Fish Pass can help you to:
Establish a project and determine its budget.
Design the equipment suitable for the site.
Supply the modules required.
Install the equipment, complete with its fixing system and hydraulic input.
Download data sheet Pre-fabricated modular eel ladder
Eel pass for gauging stations
The fixed sills of gauging stations can constitute obstacles to the upstream migration of eels. Fish Pass proposes a simple solution based on eel brushes.
Download data sheet Gauging-station-pass